// 
//  Copyright 2011  reda
// 
//    Licensed under the Apache License, Version 2.0 (the "License");
//    you may not use this file except in compliance with the License.
//    You may obtain a copy of the License at
// 
//        http://www.apache.org/licenses/LICENSE-2.0
// 
//    Unless required by applicable law or agreed to in writing, software
//    distributed under the License is distributed on an "AS IS" BASIS,
//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//    See the License for the specific language governing permissions and
//    limitations under the License.
using System;
using NHibernate;
using ManiacMusicManager.Data.Exceptions;
using System.Threading;
using ManiacMusicManager.Data.DAO.Ifaces;
namespace ManiacMusicManager.Data.DAO
{
	internal class SessionHolder : ISessionHolder
	{
		#region Constructeurs
		public SessionHolder (ISession session) {
			if (session == null)
				throw new ArgumentNullException ("session");
			
			if(! session.IsOpen)
				throw new ArgumentException("Passage d'une session non valide", "session");
			
			this._currentSession = session;
		}
		#endregion
		
		#region Session
		private readonly ISession _currentSession;
		
		public ISession GetSession() {
			if(! _currentSession.IsOpen)
				throw new DatabaseException(new SessionException("Accés à une session nhibernate fermée"));
			
			return _currentSession;
		}
		#endregion
		
		#region MultiThreading Management
		private readonly static object _criticalLock = new object();
		
		public void BeginSafeBlock() {
			Monitor.Enter(this.GetSession());
			Monitor.Enter(_criticalLock);
		}
		
		public void EndSafeBlock() {
			Monitor.Exit(_criticalLock);
			Monitor.Exit(this.GetSession());
		}
		#endregion
	}
}

